CROPPING SYSTEMS — WASHINGTON, OREGON, IDAHO. 
Table VI. — Results of seeding clover with a nurse crop in that portion of eastern Wash- 
ington, eastern Oregon, and northern Idaho having an annual precipitation of 20 inches 
or more. 
Nurse crop. 
Number Acres 
of trials. 1 tried. 
Acres 
success. 
Per cent 
success. 
17 141 
18 294 
33 388 
32 684 
107 
284 
348 
75.9 
Spring wheat 
96.5 
Oats 
89 7 
Barlev 
669 j 97.8 
Total 
100 1,507 1.408 i 93.4 
It will be seen from Table VI that the number of trials and the 
total number of acres seeded to clover were sufficient for drawing 
definite conclusions. The trials covered a period of 11 years (from 
1904 to 1916, inclusive, with no trials in 1905 or 1908), which is a 
sufficient length of time to eliminate the question of variation in 
climatic conditions from season to season. In the 100 trials reported 
there were 1,507 acres of clover seeded, with four different nurse 
crops. A good stand was obtained on 1,-108 acres, or 93.4 per cent 
of the area seeded. Barley proved to be the best nurse crop, as a 
good stand of clover was secured on 97.8 per cent of the area seeded 
in barley as compared with 96.6 per cent of the area seeded in spring 
wheat, 89.7 per cent of the area seeded in oats, and 75.9 per cent of 
the area seeded in winter wheat. The high percentage of failure when 
clover was seeded in the spring with winter wheat is attributable 
to the fact that the wheat was too far advanced when the clover was 
sown. Very good results, however, have been obtained when the 
clover was sown in the very early spring before the wheat plants 
began growing. 
When clover is to be seeded in the spring with winter wheat, from 
8 to 10 pounds of seed per acre is sown and harrowed in before the 
grain starts growing. If the nurse crop is to be spring grain, the 
ground should be plowed in the fall or very early spring and worked 
into a mellow, shallow seed bed 2 or 3 inches in depth. It is very 
important that the subsurface below this depth be quite firm. From 
8 to 10 pounds of clover seed per acre may be sown broadcast by 
hand or with a wheelbarrow grass seeder after the nurse crop has 
been seeded. The usual method, however, is to sow the grain and 
clover at one operation, using a grain drill having a grass-seed at- 
tachment. The clover seed should not be run into the grain tubes 
of the drill, as the seed are liable to be planted to such a depth that 
the plants will not reach the surface of the ground. The depth of 
planting should never be greater than lh inches. The drag harrow 
should be run immediately behind the drill. In case the ground is 
very loose a corrugated roller may be used to advantage in securing 
a stand of clover. 
